Alkylation is an important reaction that is conducted very frequently in chemical industries. However, in the case when alkylation is conducted in an industrial scale, the problem of safeness and risk are significant. For example, reactions have been habitually conducted by using highly toxic chemical substances or at a high temperature in many cases, and in the case when these reactions are carried out in an industrial scale, they have the problem of high toxicity.
Examples of conventional alkylation include 1) a process using sulfuric acid or hydrogen fluoride as a catalyst (see Non-Patent Literature 1), and 2) a process using a catalyst containing aluminum chloride (see Non-Patent Literature 2). However, since either of these processes uses an acid or halogen-containing substance having high corrosiveness, a countermeasure for preventing corrosion of apparatuses and a post-treatment for separating and collecting the reacted catalyst are necessary, and thus the steps are complicated. Therefore, either of known processes was not suitable as an industrial process and was not sufficiently suitable.
In order to make easily the separation of a catalyst after a reaction, a solid catalyst that is readily separated and collected from a reaction liquid is preferable, but the activity thereof is not suitable. For example, it was reported that a Friedel-Crafts alkylation of toluene and cyclohexene was conducted by using a solid catalyst, but the reaction was performed by adding a solid catalyst containing an inorganic structural material showing an acidic property such as a zeolite and a clay in an amount equal to or more than the amount of the cyclohexene as a raw material (see Non-Patent Literature 3). It is difficult for carrying out in an industrial scale to use 100% or more by mass of a solid catalyst with respect to raw materials.